I have a 2000 GMC Sierra 4.8 and recently replaced the Idle Air Control. Now it idles too high and is slow to come down from any throttle inputs. I disconnected the IAC and the throttle seemed a lot better aside from a slightly low idle. I understand the computer needs to relearn the new part. I have tried disconnecting the battery for 30 minutes, letting it run for 5 minutes then turning it off, and driving it at 55 and allowing it to coast down to 45 but that doesn't work with the high idle it stays at 55. Help. Thanks in advance.
